Spark plugs are without doubt you machines weak spot.We know that sometimes your too busy riding to stop and check your spark plugs, however ignoring them is going to lead to a breakdown. Check them against this chart and let them tell you how your motorcycle is feeling. Just click on the chart below to get an expanded view and compare your plug to see how the engine is preforming.

Spark plug readings are only valid for the most recent engine operating conditions and running the engine under different conditions may erase or obscure characteristic marks previously left on the spark plugs. Thus, the most valuable information is gathered by running the engine at high speed and full load, immediately cutting the ignition off and stopping without idling or low speed operation and removing the plugs for reading